From 1ebca05f5cb04162e124e59cac701291f23d9091 Mon Sep 17 00:00:00 2001 From: Jae Hyun Yoo Date: Wed, 13 Mar 2019 15:27:48 -0700 Subject: [PATCH] misc: Add clock control logic into Aspeed LPC SNOOP driver If LPC SNOOP driver is registered ahead of lpc-ctrl module, LPC SNOOP block will be enabled without heart beating of LCLK until lpc-ctrl enables the LCLK. This issue causes improper handling on host interrupts when the host sends interrupt in that time frame. Then kernel eventually forcibly disables the interrupt with dumping stack and printing a 'nobody cared this irq' message out. To prevent this issue, all LPC sub-nodes should enable LCLK individually so this patch adds clock control logic into the LPC SNOOP driver. Signed-off-by: Jae Hyun Yoo --- arch/arm/boot/dts/aspeed-g4.dtsi | 1 + arch/arm/boot/dts/aspeed-g5.dtsi | 1 + drivers/misc/aspeed-lpc-snoop.c | 30 +++++++++++++++++++++++++++--- 3 files changed, 29 insertions(+), 3 deletions(-) diff --git a/arch/arm/boot/dts/aspeed-g4.dtsi b/arch/arm/boot/dts/aspeed-g4.dtsi index 3a7e31f3de07..bedfb77c0158 100644 --- a/arch/arm/boot/dts/aspeed-g4.dtsi +++ b/arch/arm/boot/dts/aspeed-g4.dtsi @@ -316,6 +316,7 @@ compatible = "aspeed,ast2400-lpc-snoop"; reg = <0x0 0x80>; interrupts = <8>; + clocks = <&syscon ASPEED_CLK_GATE_LCLK>; status = "disabled"; }; diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi index a6720bc952b0..a26e8b3c09bf 100644 --- a/arch/arm/boot/dts/aspeed-g5.dtsi +++ b/arch/arm/boot/dts/aspeed-g5.dtsi @@ -451,6 +451,7 @@ compatible = "aspeed,ast2500-lpc-snoop"; reg = <0x0 0x80>; interrupts = <8>; + clocks = <&syscon ASPEED_CLK_GATE_LCLK>; status = "disabled"; }; diff --git a/drivers/misc/aspeed-lpc-snoop.c b/drivers/misc/aspeed-lpc-snoop.c index 2feb4347d67f..39a0471f0b8f 100644 --- a/drivers/misc/aspeed-lpc-snoop.c +++ b/drivers/misc/aspeed-lpc-snoop.c @@ -15,6 +15,7 @@ */ #include +#include #include #include #include @@ -71,6 +72,7 @@ struct aspeed_lpc_snoop_channel { struct aspeed_lpc_snoop { struct regmap *regmap; int irq; + struct clk *clk; struct aspeed_lpc_snoop_channel chan[NUM_SNOOP_CHANNELS]; }; @@ -286,22 +288,42 @@ static int aspeed_lpc_snoop_probe(struct platform_device *pdev) return -ENODEV; } + lpc_snoop->clk = devm_clk_get(dev, NULL); + if (IS_ERR(lpc_snoop->clk)) { + rc = PTR_ERR(lpc_snoop->clk); + if (rc != -EPROBE_DEFER) + dev_err(dev, "couldn't get clock\n"); + return rc; + } + rc = clk_prepare_enable(lpc_snoop->clk); + if (rc) { + dev_err(dev, "couldn't enable clock\n"); + return rc; + } + rc = aspeed_lpc_snoop_config_irq(lpc_snoop, pdev); if (rc) - return rc; + goto err; rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 0, port); if (rc) - return rc; + goto err; /* Configuration of 2nd snoop channel port is optional */ if (of_property_read_u32_index(dev->of_node, "snoop-ports", 1, &port) == 0) { rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 1, port); - if (rc) + if (rc) { aspeed_lpc_disable_snoop(lpc_snoop, 0); + goto err; + } } + return 0; + +err: + clk_disable_unprepare(lpc_snoop->clk); + return rc; } @@ -313,6 +335,8 @@ static int aspeed_lpc_snoop_remove(struct platform_device *pdev) aspeed_lpc_disable_snoop(lpc_snoop, 0); aspeed_lpc_disable_snoop(lpc_snoop, 1); + clk_disable_unprepare(lpc_snoop->clk); + return 0; } -- 2.7.4